DC/DC converter circuits are used to receive an input DC voltage and output an output DC voltage. Typically, the output DC voltage is different than the input DC voltage. For example, a DC/DC converter circuit may act as a step-down DC/DC converter that outputs an output DC voltage that is less than the input DC voltage. The DC/DC converter circuit may act as a step-up DC/DC converter that outputs an output DC voltage that is greater than the input DC voltage. DC/DC converter circuits may also be used for other purposes, such as to provide noise isolation or regulate voltage levels.
Referring now to FIG. 1, an exemplary boost (step-up) DC/DC converter circuit 10 includes an inductor 12, one or more semiconductor switches such as a transistor 14, a diode 16, and an output capacitor 18. The converter circuit 10 receives an input voltage Vin across voltage inputs 20 and 22 and outputs an output voltage Vout across the output capacitor 18. The operation of the transistor 14 determines the inductor current. For example, when the transistor 14 is ON, the inductor current increases. When the transistor 14 is OFF, the inductor current decreases. In this manner, switching the transistor 14 ON and OFF controls the inductor current and the output voltage Vout. A DC/DC control module 24 generates a switching control signal (e.g. a PWM signal) 26 that switches the transistor 14 ON and OFF.